Now, let's briefly look at each one of those ideas:
A Retreat in will likely include sightseeing excursions with a local guide, lectures, prayer and discussion periods, include possible guest lecturers besides you, yourself, and accommodations and meals will often be in Guest houses, active or former monasteries, convents), or quieter hotels which are located outside the city centers. Pricing is often less for this type of lodging - although not always, but it can be - and meals are good but more simple.
A Theological Seminar or short-Course will have similar requirements to a Retreat, but need classroom or meeting spaces with audio-visual equipment, access to internet and proximity to libraries, museums, and of course lodging and meal arrangements for all of the instructors as well as the students or conference attendees.
The next post I'll tackle the differences between a Pilgrimage and a Faith Heritage Tour. Until next time, God Bless!